Carbon coils could be synthesized on nickel catalyst layer-deposited silicon oxide substrate using and as source gases under thermal chemical vapor deposition system. By the incorporation of additive in cyclic modulation manner, the dominant formation of the nanosized carbon coils could be achieved with maintaining the minimized sulfur additive amount. The geometry variation of the as-grown carbon coils, such as linear type, microsized coil type, wavelike nanosized coil type, and nanosized coil type, were investigated according to the different cyclic modulation manner of flow. gas incorporation develops the coil-type geometry. Furthermore, the higher flow rate of gas increased the amount of the nanosized carbon coils. The slightly increased etching ability by addition seems to be the cause for these results.

FeNi alloy nanofibers have been prepared by an electrospinning process followed by air-calcination and H2 reduction to develop electromagnetic (EM) wave absorbers in the giga-hertz (GHz) frequency range. The thermal behavior and phase and morphology evolution in the synthetic processes were systematically investigated. Through the heat treatments of calcination and H2 reduction, as-spun PVP/FeNi precursor nanofiber has been stepwise transformed into nickel iron oxide and FeNi phases but the fibrous shape was maintained perfectly. The FeNi alloy nanofiber had the high aspect ratio and the average diameter of approximately 190 nm and primarily composed of FeNi nanocrystals with an average diameter of ~60 nm. The FeNi alloy nanofibers could be used for excellent EM wave absorbing materials in the GHz frequency range because the power loss of the FeNi nanofibers increased up to 20 GHz without a degradation and exhibited the superior EM wave absorption properties compared to commercial FeNi nanoparticles.

There are many restrictions in conventional ways of Jewelry mass production which are Mokume Gane, Inlaid Technology based on a joining work of dissimilar metals. To overcome this, Multi-Casting using both Jewelry-Casting and CAD/CAM has presented. In experiment on Muti-Casting, second original sample which was produced by CAD/CAM is 5 % smaller than first one. The first and second castings are brass and silver, respectively. When making second sample, the temperature of flask was about higher than the standard temperature of flask when making castings. Through the Multi-Casting, it was found that there was no trouble making dissimilar metals Jewelry which can be mass produced.

Inconel 617 and Hastelloy X are the most promising candidate materials for the heat exchanger of next generation nuclear reactor. Surface coating and its effects on high temperature properties for the Inconel 617 and Hastelloy X under molten FLiNaK (LiF-NaF-KF) salt environment have been investigated. For TiAlN and overlay coatings, the two different PVD (physical vapor deposition) methods of an arc discharge and a sputtering were applied, respectively. A study for the thermal stability of the surface modified Ni-Cr alloy substrates has been conducted. To evaluate the corrosion mechanism of Ni-Cr alloys in the molten salt, a ruptured Inconel pipe used for the molten salt transportation has been analyzed. The thermal properties of morphological and structural properties each sample were characterized before and after heat-treatment at in molten FLiNaK salt. The results showed that the TiAlN and overlay coated specimens had the enhanced high temperature stability.

, co-doped ( : ) specimens have been successfully synthesized via the complex citrate-gel method and their structural and optical properties were investigated in detail. Under 980 nm excitation, : UC phosphors have been emitted strong green luminescence at 530 and 550 nm with weak red emission around 670 nm corresponding to the intra 4f transitions of (, , ) (). The optimal doping concentrations of and ions were verified to 2/16 mol% and a possible upconversion mechanism depending on pump power dependence is studied in detail.

In this study, two pretreatment methods were used to improve the sinterability of zirconium diboride (). As a mechanical treatment, as-received powder was crushed using SPEX mill from an average size of to . As a chemical treatment, oxygen contents of powder were decreased from 4.20 wt% to 2.22 wt% using a dilute hydrofluoric solution. The relative density of sintered increased with decreasing particle size and oxygen contents. But it is considered that particle size is more effective than oxygen contents for densification. Through the two pretreatment processes, we produced sintered ceramic with a full density without sintering additives. The sinterability of was improved by using mechanical and chemical pretreatment methods.

The mechanical property enhancement was studied using fly ash produced from fluidized bed type boiler in power plant, which contains a lot of Ca component being used to carbonate for fixation in the lightweight aggregates made of cement and some portion of fly ash as a cement substitution under the supercritical condition. Specimens having various fly ash substitution rates and curing periods were carbonated under the supercritical condition at . The weight change rate, carbonation rate by TG/DTA analysis, 1% Phenolphthalein test, specific gravity and mechanical compression strength test were performed to observe the mechanical property enhancement of the cemented materials after carbonation under the supercritical condition and to make sure those could be classified as lightweight aggregates having specific gravity under 2.0.